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-Structure paper
Title | CryoEM and computer simulations reveal a novel kinase conformational switch in bacterial chemotaxis signaling. |
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Journal, issue, pages | Elife, Vol. 4, Year 2015 |
Publish date | Nov 19, 2015 |
Authors | C Keith Cassidy / Benjamin A Himes / Frances J Alvarez / Jun Ma / Gongpu Zhao / Juan R Perilla / Klaus Schulten / Peijun Zhang / |
PubMed Abstract | Chemotactic responses in bacteria require large, highly ordered arrays of sensory proteins to mediate the signal transduction that ultimately controls cell motility. A mechanistic understanding of ...Chemotactic responses in bacteria require large, highly ordered arrays of sensory proteins to mediate the signal transduction that ultimately controls cell motility. A mechanistic understanding of the molecular events underlying signaling, however, has been hampered by the lack of a high-resolution structural description of the extended array. Here, we report a novel reconstitution of the array, involving the receptor signaling domain, histidine kinase CheA, and adaptor protein CheW, as well as a density map of the core-signaling unit at 11.3 Å resolution, obtained by cryo-electron tomography and sub-tomogram averaging. Extracting key structural constraints from our density map, we computationally construct and refine an atomic model of the core array structure, exposing novel interfaces between the component proteins. Using all-atom molecular dynamics simulations, we further reveal a distinctive conformational change in CheA. Mutagenesis and chemical cross-linking experiments confirm the importance of the conformational dynamics of CheA for chemotactic function. |
External links | Elife / PubMed:26583751 / PubMed Central |
Methods | EM (tomography) / EM (subtomogram averaging) |
Resolution | 11.3 - 17.5 Å |
Structure data | EMDB-3234: EMDB-6319: Structure of bacterial chemotaxis signaling CheA2-trimer core complex by cryo-electron tomography and subvolume averaging EMDB-6320: |
Source |
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Keywords | SIGNALING PROTEIN / bacterial chemotaxis / core-signaling unit / adaptor protein / histidine kinase / chemoreceptor |